For example, some of the portable devices (hereafter referred to as PDs) such as the Network Walkman (trademark), digital still cameras, digital video cameras, IC recorders, personal computers, and other electronic equipment may use detachable semiconductor memories such as the Memory Stick (hereafter referred to as MS).
One MS may be shared by some of the above-mentioned electronic devices of different types as long as its storage capacity allows. For example, one MS may be loaded in a digital still camera and, after recording image data into it, this MS may be loaded on an IC recorder to record audio data or loaded on a personal computer to record given data.
However, if one MS is shared between a plurality of electronic devices as mentioned above, the storage capacity of the MS may run short because it already stores data recorded by another device. If this happens, the data recorded by another device may be temporarily moved to another recording medium (for example, the MS may be loaded on a personal computer and the data stored in the MS may be moved to the hard disk drive of the personal computer).
This requires time and labor for the user in selecting, by using a personal computer, the data to be temporarily moved from the MS to another recording medium. It is also troublesome for the user to restore the data temporarily moved to another recording medium back to the MS.